Open-GraphEq is a robust graphing application for mathematical formulae with 2 variables.
It is an open source alternative to the shareware GrafEq.
Both GrafEq and Open-GraphEq are based on the methods described in Reliable Two-Dimensional Graphing Methods for Mathematical Formulae with Two Free Variables by Jeff Tupper of University of Toronto, SIGGRAPH 2001.
The screenshot shows Open-GraphEq displaying a finished graph of y < 1/x. There is also a demo screencast.
Legend:
- White areas – no solutions
- Black areas – proven solutions
- Purples lines – progressively-refined grid used in the calculation
- Graphing engine based on interval arithmetic
- Toggleable grid display
- Optional domain tracking
- Care has been taken to produce accurate results
- Optional subpixel refinement
- Optional continuity tracking
- Formula editor
- Verify floating point accuracy
Open-GraphEq uses Shake. Other than that, its sole dependency is rolmodl. In addition to the system-defined lib and include paths, the build system looks for the rolmodl shared library in ./lib/rolmodl/, and for the rolmodl header files (./src/rolmodl/hpp/*) in ./lib/rolmodl/hpp.
After installing the dependencies, simply run ./build.sh from the project folder.
Use ./run.sh to run the application once built.
| Key | Action |
|---|---|
| Esc | Exit |
| G | Toggle grid |
| Enter | Finish graph (does not keep track of grid refining) |
| Space | Take a step in the graphing process |
Use the mouse to select a region and dump the intervals it describes to stdout.

